When repair work is required on structures, such as vehicles or the skin of an aircraft, for example, it may be necessary to take into account the size, shape and location of previous damage and/or repairs for optimum repair of the structure. Photographs of the previous damage and/or repair may be made but may not be precisely located or sized on the structure or may not be useful for future repair planning. During the analysis of a damage/repair site (i.e. a location of interest) it may be desirable to obtain measurement information without contacting the structure. Due to accessibility and/or contact constraints, it may be difficult to reach the location of interest to obtain position measurements.
Local positioning systems which have been used to determine the location, shape and size of damage and/or repairs on structures, such as skin damage and/or repairs on an aircraft, for example, may utilize acoustic, laser-based, magnetic, RFID, GPS, and motion capture-based systems. A local positioning system may utilize a minimum of four wireless acoustic sensors (and may require line-of-site) to provide 3-D positioning capability of past damage and/or repairs. The sensors may require mounting on the structure with the fourth sensor used to generate point data. Also, curvature of any sort on the surface of the structure distorts the acoustic path and reduces the precision to the point that this method will not work in many cases.
Laser-based positioning systems may stand off the structure to take location data on a structure. Other laser-based systems require receivers or reflectors placed at locations of interest. Multiple laser emitters may need to be placed around the work volume, which increases process complexity and data collection effort of the user. In a similar manner, motion capture (MoCap) systems may also require the placement of components around the work volume, in this case multiple camera units, and also require the placement of markers on the target object. Other systems also have shortcomings as well, such as magnetic systems that which require placement of magnetic sensors and tend to have accuracy problems due to interference from any metal on a structure. Global Positioning Systems and active RFID-based systems don't have the necessary resolution, and also require device placement on the target object.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.